Process for producing aluminum from clay, kaolin, and other aluminum silicates.



PROCESS FOR PRODUCING ALUMINUM FROM CLAY, KAOLIN,

6. MELLEN.

APPLICATION FILED AUBJI. I912,

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Patented Nov. 16, 1915.

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6 ZJJE/ UNITED STATES PATENT OFFICE;

GBEHVILLE HELLER, OF EAST ORANGE, NEW JERSEY, ABBIGNOB OI cam-m1 IQUNITED ALUIIITUQI INGOT comm, A GORPOM'IION 0! NEW YORK.

rnocass non racnucme rack CLAY, mom, an arm nmmnnc s'nacam Ipecmcaflon0! Letters Patent. 1

Patented Nov. 16, 1915.

To all whom it may concern:

Be it known that I, GRENVILLE MELLEN, a citizen of the United States,residing at East Orange, in the count of Essex and State of New Jersey,have invented certain new and useful Improvements in Processes forProducing Aluminum from Clay, Kaolin, and other Aluminum Silicates, ofwhich the following is a specification.

My invention relates to a process of treating clays, kaolin, and otheraluminum silicates, for the purpose of obtaining aluminum, by reactingupon said clays, etc., with suitable reagents, and obtainingintermediate products which are continually reused; by-products, andmetallic aluminum.

The process is also applicable for the roduction of metals similar toaluminum, rom their silicates.

The accompanying drawing illustrates diagrammatically the several stepsof the process.

The clay, kaolin, etc., is fused with sodium sulfate and sulfuric acid,or with its equivalent of sodium bi-sulfate, (NaHSO,) in suchproportions as to form aluminum sulfate, and free silica; in the formercase the sodium sulfate combining with the sulfuric acid, on heating,forming sodium acid sulfate, (NaHSOJ, which when molten serves as a fluxand decomposes the clay, kaolin, etc., fused therewith. After thereaction is completed, the mass is cooled, and dissolved in hot water,or in a hot dilute aqueous solution of sodium sulfate, containing asmall quantity of aluminum salts from a prior extraction. The hotsolution thus obtained has an acid reaction, due to sulfuric acid, andto the acid reaction of aluminum sulfate solutions, and is filtered toremove silica and any other insoluble matter contained therein. Thefiltered solution is concentrated if necessary, and a concentratedsodium fluorid solution is added thereto, with stirring. This solutionis allowed to cool, when an aluminum fluorid precipitate will se arateout. This aluminum fluorid is difiiizultly soluble, and is separated byfiltration; the filtrate containing sodium sulfate is concentrated tocrystallize out of the sodium sulfate, some of which may be used, withfresh sulfuric acid, to fuse additional clay, etc., or the e uivalent ofsodium acid sulfate, may be substituted, as above described. The

cathode, and producing sodium fluorid.

After the electrolysis has been carried as far as is deemed practicable,the fused mass of sodium fluorid, which may contain some sodium chloridand some aluminum fluorid, is tapped off, and allowed to cool; it maythen be used to precipitate aluminum fluorid from the aluminumsulfate-sodium sulfate solution, as above described. The metallicaluminum remaining from the electrolysis is tapped off and cast intoingots.

The halogen, as in the instance described, chlorin, is separated byelectrolysis from the sodium chlorid, and collected in any suitablemanner.

The byroducts from the process, using, for examp e, sodium chlorid, arehighly pure silica obtained in the first step of the process,chlorinobtained by electrolysis, and sodium sulfate.

' The intermediate products, sodium sulfatizl, and sodium fluorid, arecontinually reuse The new materials required are clay, sulfuric acid,and sodium chlorid.

I may separately fuse the sodium sulfate and sulfuric acid to formsodium acid sulfate, and fuse the clay with this salt; or I may obtainsodium acid sulfate from outside sources, and use it direct.

The ordinary chemical equivalents of the salts used, such as potassiumsalts, etc., are intended to be included by the term sodium where used;the sodium salts are preferred for commercial reasons. In lieu ofchlorid salts, bromids or iodids may be used where practicable.

I claim:

The cyclic process, which consists in fusing clay with sodium sulfateand sulfuric acid, dissolving and filtering the roduct,

the filtrate comprising}. mixture 0 alumi-r Y 1 num sulfate and so umsulfate, adding thereto a solution of sodium fluorid and therebyprecipitating aluminum fluorid; then filtering oil the sodium sulfate,crystala l g 13, 0,4 lizing and using the broduct in the In testlmonwhereof I aflix my signature of a succeeding operation; fusing the :6--in presence 0 two ei itate aluminum fluorid with e um sal t,electrolyzing the fused mass to deposi GRENVILLE MELLEN' 5 aluminum, andreusing the exha mt:

sodium-fluorid-containing electrolyte to J. W. HARRIS,

form fresh aluminum fluorld. E. C. Tn'n.

Itis hereby that in Letters Patent No. 1,160,431, granted November 16,1915, upon the application of Grenville Mellon, of East Orange, NewJersey,

for an improvement in .Proeesses for Producing Aluminum from Clay,Kaolin,

and other Ahiminum Silicatee, an error appears in the printedspecification requiring correction as follows: Page 1, line 50, strikeout the word of, and

that the said Letters Patent should be read with thie correetion thereinthat the same may conform to the reeord'of the case in the PatentOfliee.-

Signed and sealed this 26th day of June, A. 1)., 1911.

[5141...] R. F. WHITEHEAD,

Acting Commissioner qf Petents. Cl. 204--207.

